
namespace my_set
{
    template<class K> class set 
    {
        struct KeySet
        {
            const K& operator()(const K& k)
            {
                return k;
            }
        };
    public:
        typedef typename RBTree<K, K, KeySet>::iterator iterator;

        iterator begin() { return _t.begin(); }
        iterator end() { return _t.end(); }
        pair<iterator, bool> insert(const K& k) { return _t.insert(k); }
        K& operator[](const K& k)
        {
            pair<iterator, bool> ret = _t.insert(k);
            return *(ret.first);
        }

    private:
        RBTree<K, K, KeySet> _t;
    };
}
